针对现有分级多PAN太赫兹无线网络MAC(Medium Access Control)协议中存在的子网形成方案不合理以及私有CTA(Channel Time Allocation)与子网内实际负载不匹配等问题,提出了一种高效低时延的MAC层优化协议.该协议采用基于泛听的按需形成...针对现有分级多PAN太赫兹无线网络MAC(Medium Access Control)协议中存在的子网形成方案不合理以及私有CTA(Channel Time Allocation)与子网内实际负载不匹配等问题,提出了一种高效低时延的MAC层优化协议.该协议采用基于泛听的按需形成子网机制避免了子网分布不均匀以及因子网形成后没有节点加入而造成的私有CTA资源浪费的问题.在子网形成后,子微微网协调器(Piconet Coordinator,PNC)根据子网内实际负载情况自适应选择私有CTA时隙资源优化机制,让有数据传输需求的节点及时将数据发出.仿真结果表明,所提出的方案能有效地降低数据帧平均接入时延,提高吞吐量以及数据帧的传输成功率.展开更多
Central pancreatectomy(CP) is a parenchyma-sparing surgical procedure. The aims are to clarify the history and the development of CP and to give credits to those from whom it came. Ehrhardt, in 1908, described segment...Central pancreatectomy(CP) is a parenchyma-sparing surgical procedure. The aims are to clarify the history and the development of CP and to give credits to those from whom it came. Ehrhardt, in 1908, described segmental neck resection(SNR) followed, in 1910, by Finney without reconstructive part. In 1950 Honjyo described two cases of SNR combined with gastrectomy for gastric cancer infiltrating the neck of the pancreas. Guillemin and Bessot(1957) and Letton and Wilson(1959) dealt only with the reconstructive aspect of CP. Dagradi and Serio, in 1982, performed the first CP including the resective and reconstructive aspects. Subsequently Iacono has validated it with functional endocrine and exocrine tests and popularized it worldwide. In 2003, Baca and Bokan performed laparoscopic CP and, In 2004, Giulianotti et al performed a robotic assisted CP. CP is performed worldwide either by open surgery or by using minimally-invasive or robotic approaches. This confirms that the operation does not belong to whom introduced it but to everyone who carries out it; however credit must be given to those from whom it came.展开更多
High-performance multifunctional filtration membranes are highly required in treating practically complex oily wastewater systems,but still a challenge unsolved.Herein,we propose a facile route to address these challe...High-performance multifunctional filtration membranes are highly required in treating practically complex oily wastewater systems,but still a challenge unsolved.Herein,we propose a facile route to address these challenges simultaneously by simply constructing electrospun pre-oxidized polyacrylonitrile nanofibrous membrane(p-PAN NM).Given the pre-oxidation process,the p-PAN NM displays not only robust anti-corrosive tolerance against diverse corrosive media,but also superhydrophilicity/underwater superoleophobicity.Additionally,~99%separation efficiency,~100%oil-fouling recovery,and ultralong service life(up to 265 h)have been realized in separating large-scale surfactant stabilized soybean/crude oil-in-water emulsions.Furthermore,strong anti-corrosive performance against various corrosive media(e.g.,1 M HCl,1 M NaOH,or 10 wt%NaCl)has been achieved as well.Spin-unrestricted density functional theory(DFT)computations implemented in the Dmol3 modulus has been conducted to understand the robust fouling recovery and the variation of surficial wettability after pre-oxidation.These outstanding filtration functions make our NM hold great potential in separating viscous oil/water emulsions under harsh conditions.展开更多
The Birimian Baguiomo formations are located in the northern part of the Boromo greenstone belt. In this belt, the volcanic rocks (tholeiitic basalt, calcalkaline basalt, andesite) hosting the gold mineralization are ...The Birimian Baguiomo formations are located in the northern part of the Boromo greenstone belt. In this belt, the volcanic rocks (tholeiitic basalt, calcalkaline basalt, andesite) hosting the gold mineralization are located in the Kwademen-Baguiomo shear zone. This mineralization, located only a few kilometers from the Kwademen gold deposit, is uncharacterized and, together with the latter, could constitute a gold potential capable of being economically exploitable. It is in this sense that this work is carried out with a view to characterizing the gold mineralization of the Baguiomo gold panning site. To carry out this work, we have made direct field measurements, combined with microstructures, and combined all this with data from geochemical rock analysis of the basalts that are the main host formations. Geochemical data show that tholeitic basalts formed from a mantle plume that was emplaced in an oceanic plateau context. Calc-alkaline basalts and andesites are comparable to Paleoproterozoic tholeitic basalts (PTH3), which are slightly enriched in light rare earths. Fertility tests show that these basalts concentrate between 3 and 6 ppb of gold at the time of accretion, which is sufficient for remobilization of this primary gold during the Eburnian orogeny to yield a deposit of around 4 - 5 Moz. Gold mineralization is associated with pyrite crystals when the latter are disseminated in the rock mass, whereas it is associated with hematite in quartz veins concordant with S1 shear deformation. It is mainly the pyrite crystals in the pressure shadows that contain the gold grains, whose development would be synchronous with micro-shear zone reactivation during the first phase of D1<sub>B</sub> deformation. The second phase of D2<sub>B</sub> deformation, which is a crenulation or fracture schistosity, does not significantly affect the shear deformation that controls mineralization.展开更多
文摘Central pancreatectomy(CP) is a parenchyma-sparing surgical procedure. The aims are to clarify the history and the development of CP and to give credits to those from whom it came. Ehrhardt, in 1908, described segmental neck resection(SNR) followed, in 1910, by Finney without reconstructive part. In 1950 Honjyo described two cases of SNR combined with gastrectomy for gastric cancer infiltrating the neck of the pancreas. Guillemin and Bessot(1957) and Letton and Wilson(1959) dealt only with the reconstructive aspect of CP. Dagradi and Serio, in 1982, performed the first CP including the resective and reconstructive aspects. Subsequently Iacono has validated it with functional endocrine and exocrine tests and popularized it worldwide. In 2003, Baca and Bokan performed laparoscopic CP and, In 2004, Giulianotti et al performed a robotic assisted CP. CP is performed worldwide either by open surgery or by using minimally-invasive or robotic approaches. This confirms that the operation does not belong to whom introduced it but to everyone who carries out it; however credit must be given to those from whom it came.
基金supported by the National Natural Science Foundation of China(No.52073238 and 52173301)Open Funds of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(PLN202205,SWPU)Natural Science Foundation of Sichuan Province(2022NSFSC0356).
文摘High-performance multifunctional filtration membranes are highly required in treating practically complex oily wastewater systems,but still a challenge unsolved.Herein,we propose a facile route to address these challenges simultaneously by simply constructing electrospun pre-oxidized polyacrylonitrile nanofibrous membrane(p-PAN NM).Given the pre-oxidation process,the p-PAN NM displays not only robust anti-corrosive tolerance against diverse corrosive media,but also superhydrophilicity/underwater superoleophobicity.Additionally,~99%separation efficiency,~100%oil-fouling recovery,and ultralong service life(up to 265 h)have been realized in separating large-scale surfactant stabilized soybean/crude oil-in-water emulsions.Furthermore,strong anti-corrosive performance against various corrosive media(e.g.,1 M HCl,1 M NaOH,or 10 wt%NaCl)has been achieved as well.Spin-unrestricted density functional theory(DFT)computations implemented in the Dmol3 modulus has been conducted to understand the robust fouling recovery and the variation of surficial wettability after pre-oxidation.These outstanding filtration functions make our NM hold great potential in separating viscous oil/water emulsions under harsh conditions.
文摘The Birimian Baguiomo formations are located in the northern part of the Boromo greenstone belt. In this belt, the volcanic rocks (tholeiitic basalt, calcalkaline basalt, andesite) hosting the gold mineralization are located in the Kwademen-Baguiomo shear zone. This mineralization, located only a few kilometers from the Kwademen gold deposit, is uncharacterized and, together with the latter, could constitute a gold potential capable of being economically exploitable. It is in this sense that this work is carried out with a view to characterizing the gold mineralization of the Baguiomo gold panning site. To carry out this work, we have made direct field measurements, combined with microstructures, and combined all this with data from geochemical rock analysis of the basalts that are the main host formations. Geochemical data show that tholeitic basalts formed from a mantle plume that was emplaced in an oceanic plateau context. Calc-alkaline basalts and andesites are comparable to Paleoproterozoic tholeitic basalts (PTH3), which are slightly enriched in light rare earths. Fertility tests show that these basalts concentrate between 3 and 6 ppb of gold at the time of accretion, which is sufficient for remobilization of this primary gold during the Eburnian orogeny to yield a deposit of around 4 - 5 Moz. Gold mineralization is associated with pyrite crystals when the latter are disseminated in the rock mass, whereas it is associated with hematite in quartz veins concordant with S1 shear deformation. It is mainly the pyrite crystals in the pressure shadows that contain the gold grains, whose development would be synchronous with micro-shear zone reactivation during the first phase of D1<sub>B</sub> deformation. The second phase of D2<sub>B</sub> deformation, which is a crenulation or fracture schistosity, does not significantly affect the shear deformation that controls mineralization.
